Physical and mechanical properties of some hybrid corn varieties

The aim of this study was to determine the structural designing parameters of silo and bins used for storage of some hybrid corn varieties(Zea mays L.).In the research,three corn varieties-dentcorn(Zea mays indentata Sturt.),popcorn(Zea mays everta Sturt.),sweetcorn(Zea mays sacharata Sturt.)-widespread cultivated in Turkey were used.Physico-mechanical parameters(bulk density,true density,angle of internal friction,static coefficient of friction)were considered as the dependent variables,and moisture content(8%,10%,12%,and 14%)as the independent variable.The bulk density,true density and angle of internal friction varied from 608.46 to 856.46 kg/m^(3),950.88 to 1110.89 kg/m^(3),and 25.2°to 34.2°,respectively,with the increase in moisture content from 8% to 14%.According to results of the research,the highest average value for bulk density,true density,angle of internal friction were found in popcorn variety(839.17 kg/m^(3)),popcorn variety(1074.40 kg/m^(3)),sweetcorn variety(30.50°),respectively.The highest average value for static coefficient of friction at concrete surface(C30)was recorded in dentcorn variety(0.662).

Relationship between single and bulk mechanical properties for zeolite ZSM5 spray-dried particles

In this work typical mechanical properties for a catalyst support material, ZSM5 （a spray-dried granular zeolite）, have been measured in order to relate the bulk behaviour of the powder material to the single particle mechanical properties. Particle shape and size distribution of the powders, determined by laser diffraction and scanning electron microscopy （SEM）, confirmed the spherical shape of the spray-dried particles. The excellent flowability of the material was assessed by typical methods such as the Hausner ratio and the Cart index, This was confirmed by bulk measurements of the particle-particle internal friction parameter and flow function using a Schulze shear cell, which also illustrated the low compressibility of the material. Single particle compression was used to characterize single particle mechanical properties such as reduced elastic modulus and strength from Hertz contact mechanics theory. Comparison with surface properties obtained from nanoindentation suggests heterogeneity, the surface being harder than the core. In order to evaluate the relationship between single particle mechanical properties and bulk compression behaviour, uniaxial confined compression was carried out. It was determined that the Adams model was suitable for describing the bulk compression and furthermore that the Adams model parameter, apparent strength of single particles, was in good agreement with the single particle strength determined from single particle compression test.